EP-A1-0253966 describes a mold part clamping element for the fixing of a tube inserted into it in an axial direction and for eliminating the radial clearance prior to making the welded connection. The clamping element is either a tightening nut with a conical squeezing portion or a clamping strip or band at the external periphery of a bushing portion. Wire ends of a heating device comprising two heating mats are arranged in a parallel circuit and are made to exit on the ends of the molded part. Such structure however virtually prevents the arrangement of a fixed plug-in connection at the external periphery of the bushing for a rapid connection with a welding aggregate. Indeed, such connection is possible only by lengthening the molded member because of the space requirement for the clamping element.
Such structure also increases the fabrication expense of the molded part because of the type of the clamping element and the design of the heating device.
It is therefore an object of the present invention to provide a molded part which facilitates fixation in place of the inset tube with a simple means prior to the welding operation.
Another object of the invention is to provide a molded part wherein the arrangement of a plug-in connection for connection of the heating device to the welding aggregate is made possible without great expense because of the design of the plug-in connection.
Yet another object of the invention is to enable a simple design of the clamping device for fixation and clamping or squeezing of the inserted tube prior to the welding operation using only commercially available screws.
A further object of the invention is to make possible the arrangement of a plug-in device at the bushing end for connecting the heating coil to a welding aggregate.